Adjustable standard



April 30, 1935. 1= MCELROY ADJUSTABLE STANDARD Filed Feb. 13, 1935 Almflllfulflmllld .lllulv llllllllllllllllllllllllllllllllll Il V'such ashair ,driers, therapeutic lamps, and ldepositionln dotted lines;

Patented Apr. 3o, 193s 1,999,844 i Y UNITED STATES PATENT; -.-O'FFICE1 lI flgggg TK f i ADJUSTABLE sremuiitliv Isaac McElroy, Minneapolis,`YApplication February 1s, 1933, serial No. 656,393

' 2 clanes.V (ci. 24a-z) Myinventionrelates to standards for wide geninwhich the movable portion thereof. is shown eral use, such as insupporting various appliances in al raised position in full linesl andin a lowered vices of many other classes, and Vmore particu- Fig. 2 .isa vertical longitudinal section of my larly to standards which areadjustable in' height. adjustable standardsV Y -V l v various adjustablestandards now in use require Fig- 3 is a cross sectional view takenalonsthe set screws and other manually operated clamping .lines-3 3 0fFig. 2, asindicated bythe aIIOWS; devices to hold themin the desiredposition.; .The Fis.y 4 is s crosssectonal viewtaken alone thek setscrews and clamping devices make necessary lined-4 0f Fig. 2J asindicated by the SHOWS; e

l0 an additional operation injchanging the adjust- 'Ifig. 5 isacross-sectional-view taken through a 10 ment and detract; from thesymmetrical appear.; modied form of the circumferentially disposed anceofsuch standards. Some adjustable standfrCtiOnal grppingelements; andards now in use are of suchconstruction that it is V1:1'8- 6 is@Veltdl-CYOSS Sectional View 0f an* necessary for the user to support orlift all or a. other modied form 0f thecircumferentially diS- verysubstantial part of the weight of theappli- DOSed fICtiOnal grippingelements. 1 -15 ance supported thereby whenv readjusting the Referringtothe drawing, a base is shown comheight of the standard. Drising a cage1, arms, ai filip-Shaped arm re- It is an object of my invention toprovide an taining member l9,.-a cap screw I II, and-casters I Iadjustable standard of the class describedwhereconstructed; inaccordance with my Pedestal 2o in the movable portion of the standard isheldk in structure for standards disclosed in United 2o Y position bymeans other than set screws or clamps, States Letters Patent No'.1,789,905. The lower such means being automatic and requiring no'enddfdtublllar ,CaSing uisligdly SeGulCd. Within manual operation. Y thecagei 'I oi the base B-,saidcasing extending A further object of myinvention is to provide Some distance upward from the top ,ofV the base.an Vadjustable standard of the classl described A tubular column I3 ofsomewhat smaller diame- 25 wherein the movable portion thereof togetherter. than the interior diameterof the casing I2 with the appliancecarried thereby, may be moved is concentrically disposed-Within `theCasing and upward or downward to-anydesired one of an inextends abovethetop endOf the Casing. 'A can I4 nite number of predetermined positionsby the provided at itsupper end with aniaperture adaptapplication of aslight amount Yof pressure in ed-to loosely receive theftubularcolumnI3` is 30 the directionof the desired movement, and `wherethreadedlyengaged with the exterior or the in means, not requiring manualoperation, isvprouppernd 0f k13h@ Casing 2"00 clse'the Samevided toautomatically Vmaintain the standard in Within the cap I4 are twowashers I5 with com- Y the desired position. Y pressiblepacking-materialy I6 therebetween, said' A still further and morespecific object is to washers encircling the tubular column and being 35provide an adjustable standard of the class deabutted respectively'A bythe top 6nd 0f the'i'flibllscribed, wherein the weight of the movablepor- 1areasing'l l2 andthetp Dltin 0f the 0211314 t0 y Y 'tion thereofand the appliance carried thereby compress the material I6. .On'themedial por-v are counterbalanced by a. spring constructed and tion-Ofthetubul/i column I3 are tWO retaining 40 proportioned to support saidweight-when the rings I'I encircling saidcolumn and .retaining 4omovable portion is at substantially its midposition absorbent vniaterial I8V therebetween, the aband to permit only a small dilerentialbetween srbent'material being in .contact with the in-A saidweightandthe supporting capacity of the terior surfacefofthe casing I2 and therings spring in other positions, andwherein frictional .being engaged'withjthe column I3 to prevent meansnotrequjring manual operation, is'prolongitudinal movement-with respect thereto. '45 vided to absorb saiddiierential and hence auto- ,Substantially midway between the retainingmatically act to vhold the movable portion in any ring I1 and the'lowe'rend of the. column I3,

' desired position. Y frictional grippingmeansis provided. A retain-These and other objects and advantages of the ing ring I9 is mounted onthe'column I3, said present invention will more fully appear from ringenclrclingthe same and having diametrical- 5o the following description,made in connection ly located' inwardly "projecting ears' projectingwith the accompanying drawing, wherein like into apertures in Saidv@011mm t0 prevent 10nyreference characters refer to the same or similargitudinalmovement of the ring therealong.- Imparts throughout thevarious Views, and, in which, mediately belowthe` ring: I9 is a seriesVof oir- Fig, 1 is a side viewwof my adjustable standard cuml'erentiallydisposed: radially movable 'fric- 55 60 The'iresistanceuto" compression.of the spring the casing I 2.

-. .the-slice rod 26.

, clude sloping Vsurfaces such that, when the wedging ring 2I is movedupwardly, wedging action will cause the vgripping elements 20 to beforced radially 'outward' against the interior surfacegof Thel lower endof columnl3V is provided with external screw threads 22 which receivethe adjusting nut-23. A helical compres-- sion and actuating spring 24surrounds column I3 and is interposed between ring 2 I and adjust'- ingnut 23 to exert an upwardpressure on said ring 2i. The reduced lower`endrof a bracket supporting headl 25, as showngis-secured within theupper end of colunm I3. A slide rod 26 is concentrically disposedVwithin the interior of columnI 3 and is threadedly engaged at its"upper end withV bracketsupport 25 and depends? to a point near thebottom end of tubular casing I2'.

Adisk 21 is disposed in the-lower endoitubular casingr I2constrained-against downward movement by supportingaears A'Zillandvacting 'as a base fof resistance for an elongatedcounter vbalancingspring 30. A"vertical tube 29 is fan-f chored` at its ,lower endv to'disk -2'1and extends axially -within column I3 'slidably surroundingThe elongated counterbalancirig `spring-f30 is of helical formandsurrounds tube29 vand ythe upper Vportion of slidelrod 2.6. rThelengthof spring 30 is preferably, when fully distendedjat least: twicethe-height' off the tubular casing I2 and over longer than the;v'maximum' distance between the base of-resistance 2l and the upperabutment (supporting hea'd 25') andv isatleast fourl times the length,wheniully 'distendedA of the range of adjustability of the standard.'4-The resistance -of the Vc'fnvinterV balancing spring 3 0 to compressionis preferablysuch in relationto the -weignt of the "column I3fand theapparatus supported by the 'column' that the apparatus will be counterbalanced Ywhen'th'ersameis1 'sub`' stantially midway between its upperlandflower limitsof adjustment, and when the same is more than 40%v(preferablyv 50%) fully compressed. The problem of perfecting mystructure so that the column i3 could be manually adjusted with-1 'itthevariation in spring pressure between the upper andlower limits ofVthe standard must be minimized inorder that frelativelygflight fric- Itional gripping means could be used.' The properrange ofthe `elongatedcoiled ,spring tothe weight supported can perhaps be' best expressedas'followsz" i utilized forthe weight supported thereby fis such thatthe weight is counter balanced ,when the spring is more than 40% 'fully`comp'ressed. The

. range of compressiony `forY allv adjusted' positions the head 25.Within the recess formed by the ange of the `washer 3i, a Hat washer 32is located. Above the flat washer is located the hub portion of abracket 33. Above the hub portion is a flat washer 34. The washers 3|,32 and 34 and the bracket 33 are secured to the upper surface of thesupporting head 25 by means of a cap screw 35 extending through alignedapertures in the elements and secured and threadedly engaged with theupper'portionv of the head25. f-

Operation" Y"'I'he tubular'column I3 supports the bracket vsupportinghead 25,' the bracket 33, and the appliance carried by the bracket andis longitudiitsiof'- movement. The spring30 is'made'relativej 1y longnfor the purpose of minimizing variation in springpressurewhen`elongation or shortening of the'fspringv takesplace due to movement'ofthe movable parts away vfrom their Amid position. While thegwork-ingrange of springcompression previouslyls'et forth will lproducegsu'ccessful'res'ults,-I prefer to use a'springof. such length andrelation Vvto vthe weight supported' .thereby that in YfullyFelevatedposition the spring will' be at least 40%coinpres'sed and in# extremelowered. position the springrwill be substantially compressed.

This results'ein the"differential, between lthe weight supported and thepressure exertedby the spring, being very small in magnitude.

The rictional gripping elements 20,"the retaining 'ringl and theactuatingring 2| are proportioned landthe spring 24 is tensioned toprovide suiiic'ientj ,gripping action to overcome the differL entialreerred vto above.VV The tension of the actuating springf24 maylbeadjusted by means of the adjusting nut 23. When itis desired toreadjustthe height of themoving portionsfof the standardla pressuresufficient to overcome the gripping action of the gripping elements 20is exerted'inthe-direction of the'Y desired movement, upon the bracket33 or any other accessible part thereof. yWhen the'desired amount yofmovement has'been'effected, the pressure'is removed and thegrippingelementsY 20 act toY maintain the moving-portion of thestandardin the-desired position. It is obvious that the movable portionof the standard may be rotated to swing the appliance through'any"desired1 angle. f

' YThe packing IB retained between the rings I5 serves -to prevententrance of dust tothe interior ofthe standard and also serves to guidethe'column I3 and prevent undesirable noise when the same isI moved.`The tube 29 and the rod" 26 cooperateto serve as a guide'for themovable parts mentioned above and forv the spring'30.

The 'absorbent material I8 retainedV between the rings: I1 is' adaptedto be saturated with oil for lubrication ofthe interior surface of thecasing I2. v m

The modified Vform of the gripping means shown in Fig. 5 includes a cap39 of diie'rent form than the cap I 4 butmounted in the same positionrelative to thetubular casing I2a. In this form, the portion of thecasing I 2a immediately adjacent the upper end thereof has a greaterexternal di'- ameter than the -main part of the casing, said portioncarrying external-screw threads for engagement lwith internal screwthreads on the cap 39. The upper end of the cap 39 includes an inclinedportion 39a slopinginward and upward toward the column I3 to fit looselyabout said column. Immediately below the inclined portion 39a, acircumferentially disposed group of gripping elements 4B, formed of woodvor other suitable material, are concentrically disposed in the annularspace between the interior of the cap and the exterior of the column I3.The upper portions of the elements d0 are inclined inward and upward toconform to the shapevof the inclined portion 39a and the lower portionsfof the elements are inclined inward and downward. Immediately below thegroup'of gripping elements 4B is an actuated ring 4 I, the upper portionof which is inclined inward and downward to conform to the contour ofthe lower portion of the gripping elements and the lower portion ofwhich is flat. Between the lower portion of the actuating ring 4I andthe upper end ofthe casing I2a, a coiled compression spring 42 isdisposed in the annular space between the interior surface of cap 39 andthe exterior surface of the column I3. The upward pressure exerted bythe spring against the actuating ring results in the ring' being forcedinward against the outer surface of the column I 3. Adjustment of thespring pressure is had by screwing the cap `39 upward or downward.

In the modified form of the circumferentially disposed frictionalgripping elements shown in Fig. 6, four segmental-shaped elements 36,similar to the gripping elements 2e shown in Figs. 2 and 3 except forhaving straight instead of inclined upper and lower sides, are disposedin the annular space defined by the retaining ring I9, the actuatingring 2l, the column I3 and the casing I2 of Fig. 2. In this modificationthe flanges of the rings I9 and 2l are bent into horizontal position,the ring 2| is anchored to the column I3 in a similar manner to the ringI 9, and the spring 24 is omitted. The opposing ends of each adjacentpair of elements 36 are provided with recesses 3l within which the endsof a helical compression spring 38 or other form of yieldable spreadingmeans are retained. The springs 38 exert pressures which force `thegripping elements 36 radially outward into contact with the interiorsurface of the casing I2.

It is apparent that I have invented a new and useful form of adjustablestandard wherein the weight of the movable portion thereof and theappliance carried by` the movable portion are counterbalanced to obviatethe necessity for the user supporting or lifting the weight of themovable parts when making a readjustment in the height of the standard.It is also apparent that I have inventeda form of adjustable standard inwhich the movable portion is automatically retained in thedesiredposition without the need of set screws or clamping devices and in whichthe need for operation of set screws or clamping devices by the userwhen readjusting the height thereof is obviated.

The device has been amply demonstrated in actual practice and has beenfound to be successful for the purposes intended.

From the foregoing description and the three forms of the inventionillustrated it will be apparent thatJ within the scope of my inventionVgripping means may be expanded outwardly to engage the outer tubularmember, as shown in Fig. 2, or may be contracted inwardly to engage theinner tubular member or column, as shown in Fig. 5.

The term gripping elements appearing in the claims is used in its broadsense to include means said support, an elongated counterbalance springmounted internally of saidy support and interposed between the lowerportion of said support and said adjustable post, a series of grippingelements arranged circumferentially of and interposed between said postand said support, means for restricting said gripping elements againstlongitudinal movement on said post, and resilient means for urging saidgripping elements radially for vengagement with said support toyieldably restrain said post from movement in either direction.

2. In an adjustable standard, .a tubular sup-- port, an adjustable postslidably telescoped in said support, an elongated counter-balance springmounted internally of said. support and interposed between the lowerportion of said support and said adjustable post, resilientmeansexpansible in a radial direction interposed between said post andsaid support for frictionally restraining said post against movement ineither direction and adapted to internally grip said support.

isAAC E. MCELROY.

